Question: a twodimensional velocity field is given by u axy2...

A two-dimensional velocity field is given by u = ax−(y/2), v = −ay+(x/2), where a is a parameter. (i) Find the streamfunction for this flow; (ii) Sketch the streamlines for 0 < a < 1/2 and a > 1/2, respectively; show the flow direction; (iii) Find the equation of the streamline through (x, y) = (1, 1)